The present invention relates in general to active bolsters for automotive crash protection systems, and, more specifically, to a system for retaining an active bolster within an interior trim panel.
In order to reduce loads applied to an occupant from impact during a vehicle crash, active bolster systems are sometimes deployed within a vehicle interior. They may be located in an instrument panel or glove box door to protect the knees or in a door panel, window pillar, or seat structures to protect against side impacts. A typical active bolster is formed from a plastic material shaped into a bellows configuration on one surface. Upon the occurrence of a crash event of sufficient magnitude, an inflator is activated to inflate the bolster and expand the bellows to create an impact cushion.
An active bolster assembly requires a mounting that ensures a proper orientation and support during a deployment toward the occupant. It must be mounted to ensure that it deploys without any obstructions or misalignments that could degrade its trajectory or performance, and preferably not produce forces that would dislodge the trim panel from its mounting to an underlying structural element. Moreover, the appearance of the bolster itself and the fit with surrounding trim must meet craftsmanship specifications such as gap size, gap consistency, and flushness.
An active bolster is typically mounted to a fixed structural element of the vehicle in order to support the bolster against expansion and to receive the forces applied against the bolster during impact with an occupant. In the case of an active side impact system, the bolster may be mounted to a door frame. A door trim substrate panel is also mounted to the door frame to provide the interior surface of the door. The trim substrate panel includes an opening for receiving the bolster, and the bolster has an outer surface with a desired color and texture to match the trim panel. With both the bolster and trim substrate panel independently mounted to the door frame, it can be a challenge to accurately control placement of the bolster within the opening so that the gap has a constant width around the periphery and so that the A-surface flushness (i.e., matching the depth of the outer surfaces) has the desired appearance. A misalignment of the bolster with the opening may introduce interference between an is expanding bolster and the trim substrate panel which could cause the substrate panel to dislodge from its installed position or the breakage of a portion of the substrate panel from the assembly.